textproduct: Albany

WHAT HAS CHANGED

PoPs increased into widespread chance category (25-35%) for Sunday night into Monday for light snow accums with and upper level disturbance and coastal low passing south of Long Island and east of the Delmarva Region.

NBM/Ensemble/Medium-Range Deterministic thermal profile guidance continues to trend warmer for the mid week for a snow/rain scenario with the best chance of snow over the northern mtns (southern Dacks/southern Greens) Wed-Thu.

KEY MESSAGES

1) Light snow from an upper level disturbance and a coastal low may allow for light snow accums that may impact the morning commute with some slick roads across eastern NY and western New England.

2) Confidence continues to increase in a prolonged period of unsettled weather conditions (snow/rain) from the middle to latter portion of next week.

DISCUSSION

KEY MESSAGE 1...

High pressure briefly builds in tonight in the wake of a cold front. The sfc high will be near NY and New England tomorrow, but mid and high clouds will quickly increase from the south and west associated with a coastal low moving northeast from the lower Mid Atlantic States. Meanwhile, an upper level disturbance will be approaching from the Great Lakes Region. A dry close to the weekend is expected after lows in the teens with with single numbers over the Adirondack Park, Lake George Region and southern VT expect highs to rebound closer to normal in the lower to mid 30s in the valleys and 20s to around 30F over the hills and mtns.

Some of the moisture from the coastal low and its mid and upper level deformation zone may interact with the northern stream short-wave trough. The northern stream short-wave is driven by cyclonic vorticity but a seeder-feeder process may actually allow the light snow to be more widespread north of the I-90 based on the 3-km HRRR. The 3-km NAMnest and latest ECMWF favors locations south and west of Albany and closer to I-84. The moisture fetch is limited, and we have raised PoPs into the chance range from 25-35% for a coating to half inch of snow with isolated higher amounts closer to an inch. The snow could impact the Monday morning commute in a few locations. Lows due to the wet bulb cooling fall back into the upper teens to mid 20s. Snow totals may have to be updated to an inch or two in spots based on the mesoscale guidance later. The NBM 24-hr probabilities ending 18Z/Mon for 0.5" of snow or greater are in the 30-50% range for Ulster/Dutchess and Litchfield Counties.

KEY MESSAGE 2... Monday and Tuesday look fairly mild with flatter mid and upper level flow setting up over the Northeast. A weak warm front may yield some scattered snow showers Monday night into Tuesday with the best chances over the southern Dacks and southern Greens. Temps by Tuesday with the higher low and mid-level heights and an influx of milder air may reach the lower to mid 40s in the valleys and lower to upper 30s over the mtns. These temps will be above normal by 5 degrees or so.

In the quasi-zonal pattern a series of weak disturbances will impact the region Wed into Fri. The ensembles and dominate clusters continue to show a couple scenarios with the boundary nearby and ptype to be an issue depending on the thermal profiles. The first wave moving moving from the Great Lakes Region across NY and New England looks to bring a bout of rain and snow before potentially transitioning back to snow late Wed night and Thu morning. The NBM supported widespread likely PoPs Wed pm with some categorical values (75-80%) for the western Dacks, western Mohawk Valley and Schoharie Valley. The best chance for rain and snow during the daytime will be over the southern Dacks and southern Greens, expect a transition to rain for the rest of the region with highs in the mid 30s to lower 40s. Snow accums look light with the warmer temps, but we will have to monitor the southern Dacks and southern Greens if moderate amounts (>4") look possible, as the latest NBM has 24-hr probs ending 7 am Thu 25-35% over the eastern Dacks and southern VT. Lows fall into the mid 20s to lower 40s.

Thu-Fri...Light pcpn may linger into Thu, but the boundary slides southward over PA or just south of the NY-PA border, though placement is uncertain into day 6 of the forecast. Another more prolific wave approaches for Friday which should bring widespread pcpn back into the region. Rain and snow look possible again, while we can not rule out a wintry mix, but forecast supports rain and snow at this point. We will continue to closely monitor trends and make adjustments to pcpn timing and ptype with the extended events in days 5 to 7.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

Through 18z/Sun...A weak disturbance continues to cross the TAF sites early this afternoon leading to mixed MVFR/VFR conditions. A few flurries will continue at KALB/KPSF for the next 2 or so hours but vsbys will remain in the VFR range. KGFL/KPOU should see mainly VFR conditions through the TAF period. KALB should see MVFR cigs at the start of the TAF period trend to VFR later this afternoon and then remain VFR through the TAF period. KPSF may maintain MVFR cigs through tonight before lifting to VFR Sunday morning. Wind will become westerly this afternoon at 5-10 kt then become variable or north to northeasterly Sunday morning at around 5 kt.

Outlook...

Sunday Night: Moderate Operational Impact. Chance of SN. Washingtons Birthday: Low Operational Impact. NO SIG WX. Monday to Tuesday Night: No Operational Impact. NO SIG WX. Wednesday to Wednesday Night: High Operational Impact. Likely RA...SN. Thursday: Moderate Operational Impact. Chance of RA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.